This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A163225 #5 Nov 23 2016 15:48:00 %S A163225 1,42,1722,70602,2893821,118611360,4861619280,199267084800, %T A163225 8167519684380,334768674223200,13721431911885600,562411325222191200, %U A163225 23052003666190808400,944850946620132384000,38727362890294069152000 %N A163225 Number of reduced words of length n in Coxeter group on 42 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I. %C A163225 The initial terms coincide with those of A170761, although the two sequences are eventually different. %C A163225 Computed with MAGMA using commands similar to those used to compute A154638. %H A163225 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (40, 40, 40, -820). %F A163225 G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(820*t^4 - 40*t^3 - 40*t^2 - 40*t + 1) %K A163225 nonn %O A163225 0,2 %A A163225 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009